Frantic Friday

“Work expands to fill the time available” — Parkinson’s First Law

I’ve had several demonstrations of Parkinson’s Law this week, and I am now a true believer. Again.

Last night, Jeff needed help using the Geometer’s Sketchpad to do some homework (due this morning at 8:30am, of course); he’d e-mailed his teacher, but no answer was forthcoming (probably because said teacher was on the train home and disconnected), and so he turned to me.

The problem seemed simple: construct a triangle with sides 15, 11, and 7, and measure one of the angles. But he couldn’t figure out how to construct the triangle.

Geometer’s Sketchpad is a very interesting program, and I wish I’d had it when I was a kid — but it isn’t particularly easy to use. It has a help system, but it’s not very helpful — and “triangle” doesn’t appear in the help system.

There isn’t even a simple way to draw a line of a specified length that you can freely move around the screen — instead, you have to construct a point, translate it by the length you want, use the two points to create a circle, then create another point on the circle, draw a line segment connecting that point to the center of the circle, and then hide the circle and the second point you constructed. After that, you have a line that you can rotate and move as you wish.

Jeff’s teacher had given them a reminder of how to do the problem — construct some circles and intersect them. But the reminder didn’t remind Jeff sufficiently, and it didn’t mean anything to me. So I told him to try looking on the web for hints — with no success.

And we kept trying to create circles of the appropriate size and position them so a triangle would magically appear — no dice.

Eventually, I suggested that he use the circle method to construct the three line segments he needed and then drag them to form a triangle. Then we un-hid the circles that he used, and voilĂ  — we knew how to construct the triangle he needed, and do it properly.

(The trick, by the way, is to construct two concentric circles, one of radius 15 and one of radius 11. Then construct a circle of radius 7 and move it so that its center is on the circle of radius 15. The points you need are the center of the circle of radius 7, the center of the circle of radius 15, and the point where the circles of radius 7 and 11 cross.)

But by that point, it was 10:30pm, and we were all very tired, having been flailing away at the problem for hours. It would have been far easier to do it with paper and pencil, but that wasn’t the point of the exercise. I guess.

Today, I arranged my own demonstration of Parkinson’s Law. I won’t go into the gory details, but suffice it to say that I was busy reading The World is Flat so that I could return it to the library and writing an evaluation of some proposals — all of which had to be accomplished by the end of the day today. I managed, but with less than 10 minutes to spare.

So I’m definitely ready for the weekend. Unfortunately, I don’t expect it to be very restful — tomorrow, we have Torah Study, services, San Jose Rep’s production of Pride and Prejudice, and then I have to pack for a week-long trip to the East Coast. I guess the flight should be restful; JetBlue doesn’t have DC power on their planes, so I can’t use my computer the whole way!